The invention relates to a spinning machine having spinning stations arranged on both sides of the machine for the spinning of yarns from slivers which are fed to the spinning stations in cans set up in several rows on a platform above the spinning machine. Guiding devices are provided between the cans and the spinning stations which guide the slivers, comprise a delivery device and are at least partly arranged on a support which is held on the spinning machine and extends upwards through the platform in the area of the center plane of the spinning machine.
A spinning machine of this type is known in the field of open-end rotor spinning on the basis of the state of the art of the German Patent Document DE 23 35 740 B2 which corresponds to U.S. Pat. No. 3,816,991. In the case of this spinning machine, the cans are arranged above on a platform and the slivers are fed to the spinning stations through guiding tubes. These guiding tubes, which are provided with baffles, are to serve as intermediate storage devices which are intermittently fed by a continuously running delivery device as a result of a special construction. In this case, the sliver is to be guided through the respective guiding tube essentially without an tensile stress. The guiding tubes, which extend upwards through the platform in the area of the center plane of the spinning machine, are used as supports for the baffles. The known patent text contains nothing concerning the holding of the platform but FIGS. 1 and 2 give the impression that the guiding tubes may be fastened to the platform as well as, in a manner not shown in detail, to the spinning machine.
The feeding of the fiber material in the form of slivers offered in cans is known also in the case of other fast running spinning machines, such as wind-around spinning machines or air spinning machines. As a rule, these are one-sided machines in which the slivers are fed to the spinning stations from above and are taken out of the cans deposited on the rear side of the spinning machine. In this case, guiding devices are provided in the form of rollers and guiding rods for the slivers.
It is also known (German Patent Document DE-PS 817 575) to feed slivers in cans in the case of ring spinning machines, in which case the cans are deposited on platforms or in a space above the spinning machine. In this case, relatively long travelling paths are obtained with one or several vertical sections which lead to the risk that the slivers may hang out, that is, will be drawn uncontrollably because of their own weight. Such an arrangement is therefore possible only for slivers which have a relatively coarse size and therefore a relatively high strength.
However, the spinning of slivers with coarse sizes is very difficult on ring spinning machines. Since the ring spinning machines have only a relatively slow delivery speed at the outlet of the drafting units, taking into account the required drafting, the feeding rollers of the drafting units must rotate very slowly, that is, at rotational speeds of one revolution per minute or less. Technically, it is extremely difficult to let long shafts, like the feeding rollers of drafting units, run at such low rotational speeds with sufficient precision. There is the danger that these shafts rotate only jerkily so that no controlled drafting is obtained. The feeding in cans of the fiber material to be spun has therefore not been carried out successfully in the case of ring spinning machines.
It is an object of the invention to develop a spinning machine of the initially mentioned type in such a manner that fine slivers may also be fed in the cans without the risk of faulty drafting, particularly in vertical sections of the transport path. At the same time, a favorable constructional arrangement of the guiding devices is to be provided.
This object is achieved according to preferred embodiments of the invention in that the delivery device comprises a conveyor belt which guides at least one sliver from the pertaining can to the spinning station, in that several spinning stations are combined to a machine section, and in that a support is provided between two machine sections respectively on which the guiding rollers of the conveyor belt are held.
In the development according to the invention, it is achieved that the slivers are supported and are nevertheless moved into the transport direction. As a result, it becomes possible to also feed relatively thin slivers in cans, that is, slivers of sizes of from approximately Nm 0.4 to 0.8. In this case, these fine slivers may also be conveyed along larger sections in the vertical direction. It is therefore possible to carry out a can feeding operation also in the case of the ring spinning machines because, as a result of the slivers of fine sizes, while taking into account the drafting, the feeding roller pairs of the drafting units still rotate at a sufficiently high speed so that a uniformly round rotating is ensured. Because of this can feeding, it will then be possible to do without a machine such as a flyer connected in front of the ring spinning machines. In the case of other spinning machines, which are provided with drafting units into which slivers are fed, it is possible to feed finer slivers so that the drafting units may then be simplified. For example, there is the possibility in the case of such machines that, instead of five-cylinder drafting units, the three-cylinder drafting units may be used which today are customary in the case of ring spinning machines.
Also in the case of open-end machines, the feeding of finer slivers results in advantages because it reduces the opening-up work for separating the fibers so that the fibers are processed more carefully during the opening-up. It is therefore possible to spin finer yarns with less damaged fibers so that the yarns have a higher quality.
The mounting of the support on the machine has the advantage that the conveyor belts, without any excessive tolerances, are from the start aligned with the pertaining spinning stations. For example, the bending-through of the platform under the weight of the cans has no disadvantageous influence. In addition, it is not required to assign a separate support for the guiding devices to each individual spinning station.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.